Short message service (SMS) is a service available on most digital mobile phones that permits the sending of short messages (also known as text messages, or more colloquially texts or even txts) between mobile phones and other hand-held devices. SMS was originally designed as part of the GSM digital mobile phone standard, but is now available on a wide range of networks, including forthcoming 3G networks.
The message payload is 140 bytes: either 160 7-bit characters, 140 8-bit characters, or 70 2-byte characters in languages such as Chinese, Korean or Japanese when encoded using 2 byte UTF-16 character encoding (see Unicode). This does not include routing data and other metadata, which is additional to the payload size.
SMS is very popular in Europe, Asia and Australia, but is relatively less used in the United States. It is so popular that the term texting (used as a verb) refers to the act of cell phone users sending SMS text messages back and forth.
It is particularly popular amongst young urbanites. In the favoured markets, it is comparatively cheap (for example, in Australia a message typically costs 20-25 Australian cents to send, whilst a voice call costs anywhere between A$0.40 and A$2.00 per minute) and it is possible to send and receive messages in noisy environments (for instance, bars) that would defeat a voice conversation.
Because of the limited message lengths and tiny user interface of mobile phones, SMS users commonly make extensive use of abbreviations, particularly the use of numbers for words, and the omission of vowels, as in the phrase "txt msg". To avoid the even more limited message lengths allowed when using Cyrillic letters, some Russians use the Latin alphabet for their own language. Predictive text software which attempts to guess words (AOL's T9) or letters (Eatoni's LetterWise) reduces the labor of multi-tap input and may make abbreviations less necessary.
Several telecommunication carriers have recently started offering so called premium rate short messages which through higher pricing and revenue sharing allows companies to be paid for their services by sending a short message. This is also becoming increasingly popular, but problems arise when the premium pricing is not advertised.
An increasing trend towards spamming cell phone users through SMS has prompted cellular service carriers to take steps against the practice, before it becomes a widespread problem. No major spamming incidents involving SMS have been reported as of October 2003, but the existence of "cell phone spam" has already been noted by industry watchdog, including Consumer Reports magazine.
SMS's have caused subtle but interesting changes in society since they became popular. Newsworthy events (in chronological order include):